We were impressed with the options available for filling the space left by the contractor original windows: both styles (double hung, casement, etc) and design options. Our front windows were about 5'x5' with half circle arches above. NT offered several design solutions: super! Windows came in a timely manner. The local installer was tremendous: expert in both removal and installation. As promised, the windows are quieter, and offer superior insulation from weather, heat and cold. The window air gap they offered appears to be greater than that of some competitors, a good thing. One (large) window had a manufacturing defect from the glass supplier (not NT). They saw to a quick replacement (2 weeks), again installed very professionally. If we have to do it again, NT would be first choice for a bid! Well satisfied.